Radio telephone system



Dec- 20, 1932 c. N. ANDERSON ET AL 89299 RADIO-TELEPHONE SYSTEM l Filed sept. 20., 1929 Hallam? 25 Indicator To Oscillator ATTORNEY vship might have Patented Dec. 20, 1932 UNITED STATES PATENT Erica CLIFFORD N. ANDERSON AND EDMUND It. TAYLOR, 0F NEW YORK, N. Y., AND SUMNER IB. WRIGHT, OF SOUTH ORANGE, NEW JERSEY, ASSIGNORS TO AMERICAN TELE- fr.

PHONE AND TELEGRAIII COMPANY, A CORPORATION 0E N YORK RADIO TELEPHONE SYSTEM i Application fiiea september 2o, '1929. seri'ai No. 394,048.

This invention relates to radio communication systems and more particularly to improvements in systems of the type which are suitable for the establishmentof telephone communication between a ship and shore. p

In the ship to shore radio system of this invention, two separate frequency bands may be utilized for transmissionV in opposite directions and separate transmitting and receivingcircuits may be provided at the shore station and at the station on the ship. In the operation of such a system, the noise from the carrier generating apparatus on the a tendency to cause interference with the speech. signals received on the ship, and radio spillover, or the speech signals transmitted from the ship, might cause echo effects in the apparatus on the ship. One of the .primary objects of the invention consists in the provision of arrangements for preventing the occurrence of interference of the above types in theapparatus on the ship. A further object of the invention consists in the provision of an improved means for monitoring on the ships apparatus and for the establishmentof communication between -the ships operator and -the subscriber .on the ship yand between the A these relays. The operation of relay 22 opensgo ships operator and the distant operator. further object of the inventi on consists in the provision of voice-operated anti-singing apparatus at the shore station to afford the privacy feature of preventing retransmission of speechoriginating on the ship by the shore transmitter. Further objects and features of the-.invention will appear more fully `from the detailed description thereof hereinafter given. y

VThe invention may be more fully understood from the followingdescription, to

lgether with the accompanying drawing in the Figures 1, 2 and 3 of which the invention is illustrated. Fig. 1 is a circuit diagram of the sending and receiving apparatus rlocated on 'the shore. Fig. 2 is a circuit diagram of the sending and receiving apparatuslocated on the ship. Fig. 3 shows in more detail, a portion of thel arrangements of Fig. 2.

Similar reference characters have been -indicator 19 might output of the amplifier. The voice currents 115 utilized to denote like parts in all oftheiigl ures.

shown a telephoneline 1 -ter hybrid coil 2 and a balancing In Fig. 1 is minating in a network 3. would be a transmitter circuit 4c and a receiver circuit 5. The transmitter circuit 4 would include an amplifier 6, in the input circuit of which would be a potentiometer 7 for adjusting volume. Bridged across the output 'i60 of amplier 6 might be a volume indicating device 8. The amplifier 6 would be connected through a delay circuit 9 to a circuit 10 which extends to the distant radio transmitter apparatus 11 and the antenna. 12.r Y A 165 receiving antenna 13 would be provided, connected to radio receiving apparatus 14. This Vapparatus would be connected by a circuit 15 to the receiver circuit 5, which receiver circuit might include a delay circuit 16 and an '.570

amplier 17. At the input iofthis amplifier there might be provided a potentiometer 18 for volume adjustingpurposes. A volume be connected across the transmitted over circuit 4; would be transmitted through a detector device 20 and over a circuit including the voice frequency operated relays 21 and 22 and would operate takingplace, the receiving apparatus will be `.90

disabled. The incoming signaling currents will be transmitted over circuit 15 and thence through the detector apparatus 23 and over y a circuit including thevoice operated relay 2li and will operate said relay. The operation of said relay will open the previously mentioned circuit including the-relays 21 and 22 and will.- thusmaintain thetransmitting circuit l ina disabledvcondition during the reception vof signals.` `Telegraph signaling Associated with the hybrid coil i525V before the voice currents 85 the windings of over.

Vradio transmitter.

apparatus such as the generator 54 and key 53 may be bridged across circuit 4.

' Ihe apparatus located on the ship will comprise a receiving antenna 25 which will be connected to the radio receiving apparatus 26. In the output of this apparatus will be included potentiometer 27 for Y adjusting volume. The output circuit 28 of the radio receiver may also have a volume indicator 30 connected thereto and will be connected to the receiver 29. A transmittingantenna 3l will be provided, connected to the radio transmitter apparatus nected to the apparatus 32 for supplying the carrier frequencies therefor. This oscillator will normally be short-circuited. The radio transmitter apparatus will be connected b the circuit 35 to a transmitter 36. A volume indicating device 38 may be included in the circuit 35 as well as a delay circuit 37 and a potentiometer device for adjusting volume.

With apparatus of this type, noise from the oscillator associated with the radio transmitter on the ship might interfere with the received speech. Furthermore, radio spillover or, in other words, the signals transmitted from the antenna 3l might cause interfering effects with the apparatus associated with the receiving antenna 25. Accordingly, the voice frequency operated relays 42 and 43 are provided. Relay 42, by means of a short circuit, normally disables ythe oscillator 33 and, hence, the radio transmitter apparatus and prevents noise from being picked up by the receiver. When the subscriber on the ship talks, the voice currents will be transmitted over the circuit 39, detector apparatus 40 and circuit 41 through relays 42 and 43 and will operate said relays. The operation of relay 42 will remo-ve the short circuit from the oscillator 33 and allow the radio transmitter 32 to function. will open the circuit connecting antenna 25 with radio receiver apparatus 26 and hence suppress noise and echoes from radio spill- Relay 43 should be adjusted Yto operate and release not later than relay 42. The delaycircuit 37 may be provided so that relay 42 will operate before the voice curJ rents from the transmitter 36 reach the radio transmitting apparatus 32.

The apparatus on the ship will also include a pair of operators receivers46 and an operators transmitter 45. By means of a switch 44, the operators equipment may be connected to the circuit in various ways. For example, when the key 44'is in its normal position,

as shown, one operators receiver 46 is con nected across the receiving circuit 28 and the other is connected by means of the circuit 50 to the output of the radio transmitter .32. Hence, the operator may monitor on the receiving circuit and also on the output of the By referring to Fig. 3,

32. An oscillator 33 is conmiddle contacts of switch The `operation of relay 43y it may be seen how the circuit 50 with the inclusion therein of detector 80 may readily connect the operators receiving set 46 to the output of the radio transmitter 32. When the key 44 is thrown tothe downward position, the operators transmitter 45 may be connected to the circuit 47 and thence be bridged across the transmitter circuit 35. In this manner,'the operator may talk to the station on the shore. If the operator desires to talk to the ships subscriber, the key 44 may be thrown to the upward position. The operators transmitter 45 will then be connected to the circuit 28 and the subscribers receiver 29. The subscribers transmitter 36 will be connect-ed over circuit 35 and thence over ciry cult 49 and the upper contacts of the switch 44 to the operators receiver 46. At the same time, a short circuit 48 will be closed bythe 44 acrossthe cir-ff cuit 41. Hence, the speech from the subscribers transmitter 36 will not affect the relays 42 and 43 and as the'radio transmitter 32 will hence be disabled, the conversation between the ships operator .and the ships sub-f' scriber will not be transmitted to the station on the shore. It is pointed out that in a system of the above type, the anti-singing voice operated arrangement shown asso-ciated with the shore station may not be required to sup-' press echoesV or singing. However, it serves a new and useful purpose in this system by providing the privacy feature of preventing retransmission of speech originating on the ship by the shore transmitter. out that if desired the arrangements of Fig. 2 might be utilized for communication with similar apparatus on another ship instead of with shore apparatus.

While the invention has been disclosed as'u embodied in certain specific arrangements which are deemed desirable, it is understood thatit is capable of embodiment in-many and other widely varied forms without departing from the spirit of the invention by the appended claims.

What is claimed is:

vl. In a system for establishing radio communi-cation between two points, terminal apparatus at one of said ceiving circuit including radio receiver apparatus, a transmitter circuit including radio transmitter apparatus, a control circuit for normally maintaining the output of said radio transmitter apparatus in a` disabled'Y condition and for maintaining the input of said radio receiver apparatus in an operating condition, an operators monitoring set connected to the output of said radio transmitter and to the output switching means for connecting said monitoring set to the input of said radio transmitter, and means controlled by said switching means in establishing said last mentioned connection for disabling said vcontrol circuit.

It is pointed-"- ,as p defined i points comprising a re-' of said radio receiver;

2. In a system for establishing radio communication between two points, terminal apparatus at one lof said points comprising a receiving circuit including radio receiver apparatus, a transmitter circuit including radio transmitter apparatus, a control circuit for normally maintaining the output of sai radio transmitter apparatus in a disabled condition and for maintaining the input of said radio receiver apparatus in an operating condition, an operators monitoring set connected to the output of said radio transmitter and to the output of said radio receiver, switching means for connecting said monitoring set to the input of said radio transmitter, means controlled by said switching means in establishingsaid last mentioned connection for disabling said control circuit, an operators transmitter, and means controlled by said switching means'for connecting said operators transmitter to said receiver circuit on the output side of the radio receiver apparatus or to said transmitter circuit on the input side of said radio transmitter apparatus.

In testimony whereof, we have signed our names to this specification this 18th day of September, 1929.

CLIFFORD N. ANDERSON. EDMUND R. TAYLOR. SUMNER B. WRIGHT. 

